QLED is an acronym that stands for Quantum-Dot Light Emitting Diode. It’s a term used by Samsung to market a new type of LED TV that uses a filter between the backlight and the screen to increase the color definition of the pixels.
OLED is an acronym that stands for Organic Light Emitting Diode. A brief explanation of this is that each of the pixels on OLED TVs emits its own light, and there is no backlight in an OLED panel.
The answer depends on what type of viewing you prefer, but OLED produces a more lifelike picture, while QLED displays provide more adequate brightness in sunlit rooms.